This invention relates to mixtures of oligomeric silicic acid esters which contain residues of perfume alcohols or biocide alcohols and which may be used, for example, for perfuming detergents because they release the perfume alcohols through hydrolysis.
The controlled release of ingredients in various preparations is the subject of numerous publications and patent applications. In the field of detergents, the accelerated or delayed release of ingredients from the group of bleaching agents, bleach activators, surfactants, etc. is of particular interest. The release of perfumes is of paramount importance in this field because both the product and the wash liquor and the articles treated therewith are intended to be intensively and lastingly perfumed. Besides applying perfumes to carrier materials and coating the perfumed carriers or encapsulating perfumes or incorporating them in compounds (for example cyclodextrin/perfume complexes), perfumes can be chemically bound to carrier media, the chemical bond being slowly broken and the perfume being released. This principle has been put into practice, for example, in the esterification of perfume alcohols, a broad prior art being available on this group of substances.
It is known from the prior art that perfume alcohols can be bound to nonvolatile siloxanes from which they are slowly released by hydrolysis. Although a broad prior art also exists on the subject of siloxane esters of perfume alcohols, problems arise where the compounds mentioned are used in detergents. Thus, many of the known compounds cannot be used in water-containing detergents and cleaners because they hydrolyze in the product itself so that the delayed release no longer occurs. This is all the more the case as conventional detergents often have pH values which further intensify the hydrolysis process. However, known siloxane esters cannot be incorporated in powder-form detergents either. Under typical production conditions for compacted particle mixtures, such as granulation or press agglomeration, the siloxane esters also tend to release the perfume alcohol during the actual production process, i.e. prematurely. Accordingly, there is a need to provide perfumes in supply forms which perfume the product and the wash liquor and substrates treated with the products, the perfume being intended to persist for a long time on textiles in particular.
Monomeric orthosilicic acid esters of perfume alcohols are described, for example, in U.S. Pat. No. 3,215,719 (Dan River Mills). This document also mentions the delayed release of perfuming alcohols from mixed esters such as, for example, bis(eugenoxy)diethoxysilane or bis(cinnamoyloxy)-diethoxysilane, the central Si atom not necessarily having to be bound to oxygen only. Oligomeric siloxane esters are not mentioned in this document.
Powder-form or granular detergent compositions which contain “perfuming” silicon compounds are described in DE 28 44 789 (Dow Corning). The mono-, oligo- and polymeric silicon compounds disclosed in this document do not have to contain a central Si atom surrounded by four oxygen atoms. Oligomeric Si compounds containing more than one perfume alcohol ester group are also not mentioned in this document.
Liquid or paste-form soap compositions containing “perfuming” silicon compounds are described in DE 30 03 494 (Dow Corning). Oligomeric Si compounds containing more than one perfume alcohol ester group are also not described in this document.
Perfuming, nonvolatile siloxanes with the general formula MaM′a.DbD′b.TcT′c.Qd where M and M′=R1R2R3SiO1/2, D and D′=R4R5SiO2/2, T and T′=R6SiO3/2 and Q=SiO4/2, where R1 to R6 independently of one another are selected from C1-40 alkyl or alkoxy and C1-40 aryl or aryloxy groups and the indices a, a′ are positive and one or more of the indices b,b′,c,c′ and d are positive or 0, are described in DE-A-197 50 706 (General Electric). Formally, oligomeric silicon compounds containing four perfume alcohol ester groups are also covered by the general formula although the document in question explicitly discloses only those compounds in which at least two carbon atoms are directly attached to an Si atom. The use of the perfuming siloxanes in detergents is not mentioned in this document either.
Accordingly, there was still a need to provide more hydrolysis-resistant siloxane esters of perfume alcohols which could even be incorporated in water-containing detergents without showing excessive signs of hydrolysis in the product itself. Another requirement to be satisfied by the compounds in question was that they should lend themselves to incorporation in granular detergent compositions without decomposing in the production process. The compounds to be produced would impart a pleasant and long-lasting perfume to the substrates treated with the solution.
Silicic acid esters corresponding to the formula:
in which R1 and R4 independently of one another are selected from the group of linear or branched, saturated or unsaturated, substituted or unsubstituted C1-6 hydrocarbon radicals and perfume alcohol radicals, each R2 and R3 independently of one another is selected from the group of perfume alcohol radicals and n assumes a value of 2 to 20,are described for this purpose in earlier, hitherto unpublished German patent application DE 19841147.2.
It has now been found that mixtures of esters of other oligosilicic acids with perfume alcohols meet the requirements stated above. In studies of these substances, it was also surprisingly found that, in combination with typical perfumes, they also provide the perfumes not esterified with the oligosilicic acids with a relatively long-lasting effect. Irrespective of the chemical composition of the perfumes, therefore, the compounds according to the invention can also be used in perfume mixtures to provide the perfume composition as a whole with prolonged perfume release. It has also been found that this release principle can thus also be applied to biocide alcohols.